This is my first cabinet and I would like some constructive feedback on my control panel.  I'm building an Ultimate Arcade II with a few minor modifications.
The control panel is 36 X 18 with two Perfect 360's and an Ultimarc T Stick plus with a ball top handle.  Spinner is Slikstik and trackball is red translucent 3" Happ.  I haven't purchased all of my buttons yet since I haven't decided on my color scheme.  
As you can see by the picture I had used this board as a template to try different layouts.  I'm leaning towards using the ergonomic layout with six buttons instead of the straight six.  If I do go that route I will do it for both setups and for the three mouse buttons as well.
I'm not committed to Neo games so I'm going to bypass the seventh button.  I will primarily be playing classic games from the 80's.
The spinner and the 4-way seem to fit about right with the natural curve of my hand.
I was trying to fit in the asteroids layout in the upper middle section but I can't seem to make it fit.  Based on research I don't think I'm going to need four buttons up by the spinner so I will probably cut that back to two.
Top level buttons will be pause,  player 1 start, player 1 credit, player 2 credit, player 2 start and exit.
I will be using a 27" arcade monitor so I will have a few inches of control panel overhang which I think is acceptable.  Based on looks I would have preferred to have it flush but I care more about having a comfortable control panel.
Think that is about it.  I welcome any thoughts or suggestions based on your past experience.  Thanks to Slikstik for the initial plan and the 116 other examples I borrowed from.